Computer networks comprise interconnected switches and routers responsible for the forwarding of packet traffic generated principally by computers as end stations. The function of each of these switches and routers is to provide an appropriate degree of isolation between various parts of the network, which has the effect of increasing the packet bandwidth available to each user of the network. The level of isolation provided by each of these elements is related to the hierarchy level in which each operates in the 7 layers defined by the OSI Reference Model. Routers operate on the user-assigned network addresses of layer 3, while switches (also known as bridges) operate using the manufacturer-assigned MAC (media access control) address of layer 2. Routers operate on layer 3 network addresses, which comprise a subnet, and a host. The router is examining the most efficient route to move data from a first subnet to a second subnet, and modifying the MAC address of the forwarded frames when moving data from one subnet to another across network addresses. Routers typically support different protocols, among which IP and IPX are common. A switch uses only information it learns from MAC addresses presented by surrounding switches or hosts, and only forwards frames within a single subnet. Since only the MAC address of each received packet is examined by the switch, it relies on fast movement of data from one port to another, based only on end-station MAC address information contained in such frames. The switching decision is then made based on simple and fast algorithms, and for layer 2 IEEE standard 802 packets, the source and destination MAC addresses are available in known locations within the frame, and can be used regardless of which layer 3 protocol is in operation. In this manner, layer 2 switches typically utilize a series of high speed, low cost state machines implemented in hardware logic for the movement of data, but are limited to switching within a single subnet. Routers, by contrast, operate on network layer 3 addresses, and whereas switches are confined to moving information within a single subnet, a router will modify the MAC addresses of the frames to enable forwarding across subnets. A new class of switch enables the router to send information to a switch such that layer 3 frames which would normally be routed between subnets are modified and forwarded between the subnets by the switch, using the forwarding information provided by the router.